1. Field of the Invention
The present invention relates generally to an antenna, and more particularly to an innovative one which is designed with a small-caliber, high-performance broadband radiator.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
According to the structural embodiments of existing broadband antennas or dual-band antennas, high and low band antennas are arranged coaxially, and also distributed in arrays to realize expected performance.
FIG. 1 depicts a plane top view of a conventional broadband antenna, which is of an array antenna structure formed by broadband radiator units 60 together with broadband radiators 70. The broadband radiator 70 consist of two dipoles 71, 72 in pair, and equilibrators 73 are used to support securely two dipoles 71, 72 at interval on a long substrate 80. The equilibrators 73 are protruded upwards in an x-frame pattern, comprising of first unit racks 731 and second unit racks 732 orthogonally to each other. A 45° included angle is formed between the setting direction of the first and second unit racks 731, 732 and the extension of the long substrate 80, then the first group of dipoles 71 are separately set at two protruding ends of the first unit rack 731, while the second group of dipoles 72 are separately set at two protruding ends of the second unit rack 732. Moreover, an orthogonal relation is formed between the setting directions of both the first group of dipoles 71 and the first unit rack 731 (90° included angle as shown by X1), meanwhile an orthogonal relation is also formed between the setting directions of both the second group of dipoles 72 and the second unit rack 732 (90° included angle as shown by X2). A 180° included angle is formed between two unit arms of the first group of dipoles 71 and second group of dipoles 72 (straight arm pattern as shown by X3). Hence, the overall dipole structure is of a diamond-shaped framework over the long substrate 80. Referring to FIG. 1, when multiple radiator units are distributed along the extension of the long substrate 80 in an elongated array pattern, the diamond-shaped dipoles 71, 72 of various radiator units are aligned by their sharp corners. However, a number of shortcomings are still observed during actual applications.
Due to a larger aperture of the broadband radiator 70 (diamond-shaped framework formed by the dipoles), the cross-polarization of high or low band antennas will deteriorate, leading to gain reduction. On the other hand, as there lacks a bigger adjustment space for the array gap of the broadband radiator 70 (indicated by L1), the interference and negative influence of the low and high band antennas will increase. If said array gap is enlarged, the extension space of the antennas will be increased substantially, leading to sharp increase of the antenna fabrication cost with lower economic efficiency and greater space occupancy.
Thus, to overcome the aforementioned problems of the prior art, it would be an advancement if the art to provide an improved structure that can significantly improve the efficacy.
Therefore, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.